package main

import (
    "fmt"
    "github.com/dvirsky/go-pylog/logging"
    "io"
    "os"
    "runtime"
    "strings"
    "sync"
    "text/template"
    "unicode"
    "unicode/utf8"
)

// +build go1.1

// Test that go1.1 tag above is included in builds. main.go refers to this definition.
const go11tag = true

const version = "0.1"

// Commands lists the available commands and help topics.
// The order here is the order in which they are printed by 'gopm help'.
var commands = []*Command{
    CmdReverse,
    CmdShell,
}

func init() {
    runtime.GOMAXPROCS(runtime.NumCPU())
}

func main() {
    logging.SetLevel(logging.ALL)
    // Check length of arguments.
    args := os.Args[1:]
    if len(args) < 1 {
        usage()
        return
    }

    // Show help documentation.
    if args[0] == "help" {
        help(args[1:])
        return
    }

    // Check commands and run.
    for _, comm := range commands {
        if comm.Name() == args[0] && comm.Run != nil {
            comm.Run(comm, args[1:])
            exit()
            return
        }
    }

    fmt.Fprintf(os.Stderr, "xorm: unknown subcommand %q\nRun 'xorm help' for usage.\n", args[0])
    setExitStatus(2)
    exit()
}

var exitStatus = 0
var exitMu sync.Mutex

func setExitStatus(n int) {
    exitMu.Lock()
    if exitStatus < n {
        exitStatus = n
    }
    exitMu.Unlock()
}

var usageTemplate = `xorm is a database tool based xorm package.
Usage:

    xorm command [arguments]

The commands are:
{{range .}}{{if .Runnable}}
    {{.Name | printf "%-11s"}} {{.Short}}{{end}}{{end}}

Use "xorm help [command]" for more information about a command.

Additional help topics:
{{range .}}{{if not .Runnable}}
    {{.Name | printf "%-11s"}} {{.Short}}{{end}}{{end}}

Use "xorm help [topic]" for more information about that topic.

`

var helpTemplate = `{{if .Runnable}}usage: xorm {{.UsageLine}}

{{end}}{{.Long | trim}}
`

// tmpl executes the given template text on data, writing the result to w.
func tmpl(w io.Writer, text string, data interface{}) {
    t := template.New("top")
    t.Funcs(template.FuncMap{"trim": strings.TrimSpace, "capitalize": capitalize})
    template.Must(t.Parse(text))
    if err := t.Execute(w, data); err != nil {
        panic(err)
    }
}

func capitalize(s string) string {
    if s == "" {
        return s
    }
    r, n := utf8.DecodeRuneInString(s)
    return string(unicode.ToTitle(r)) + s[n:]
}

func printUsage(w io.Writer) {
    tmpl(w, usageTemplate, commands)
}

func usage() {
    printUsage(os.Stderr)
    os.Exit(2)
}

// help implements the 'help' command.
func help(args []string) {
    if len(args) == 0 {
        printUsage(os.Stdout)
        // not exit 2: succeeded at 'gopm help'.
        return
    }
    if len(args) != 1 {
        fmt.Fprintf(os.Stderr, "usage: xorm help command\n\nToo many arguments given.\n")
        os.Exit(2) // failed at 'gopm help'
    }

    arg := args[0]

    for _, cmd := range commands {
        if cmd.Name() == arg {
            tmpl(os.Stdout, helpTemplate, cmd)
            // not exit 2: succeeded at 'gopm help cmd'.
            return
        }
    }

    fmt.Fprintf(os.Stderr, "Unknown help topic %#q.  Run 'xorm help'.\n", arg)
    os.Exit(2) // failed at 'gopm help cmd'
}

var atexitFuncs []func()

func atexit(f func()) {
    atexitFuncs = append(atexitFuncs, f)
}

func exit() {
    for _, f := range atexitFuncs {
        f()
    }
    os.Exit(exitStatus)
}
